PE22.9-10 | Cardiovascular Investigations — Summary & Reflection

KEY TAKEAWAYS

The chest X-ray and ECG are the two most important first-line cardiovascular investigations in children. On the CXR, assess quality and projection (AP magnifies the cardiac shadow), then systematically review the cardiac shadow size (CT ratio >0.55 in children >2 years on PA = cardiomegaly), shape (boot = tetralogy; egg-on-string = TGA; snowman = TAPVC), pulmonary vascularity (plethora = left-to-right shunt; oligaemia = right-to-left shunt; oedema = cardiac failure), and bony structures (rib notching = coarctation). On the ECG, apply a systematic approach: rate (age-specific norms), rhythm, axis (right-axis in neonates is normal), PR interval (>0.20 s = first-degree AV block), QRS duration and morphology (RVH: tall R in V1 beyond age; LVH: tall R in V5-V6), T waves (inverted V1 = normal in neonates and infants; upright V1 in neonates = abnormal = RVH), and QTc (>0.44 s prolonged; >0.47 s significant). Biventricular hypertrophy (Katz-Wachtel) suggests a large VSD; left-axis deviation in Down syndrome = AVSD; prolonged QTc + exertional syncope = LQTS. Integrated CXR + ECG interpretation with clinical examination gives the highest diagnostic yield.

REFLECT

Look back at the hook: a child with a murmur, whose CXR showed cardiomegaly and pulmonary plethora, and whose ECG showed right-axis deviation with biventricular hypertrophy. Before this module, how confident were you that you could interpret both films and integrate the findings with the clinical examination? Now that you have a systematic framework, reflect on where in your clinical placements you can practise this skill. Which settings — neonatal ward, cardiac OPD, paediatric emergency — will expose you to the most X-rays and ECGs with confirmed diagnoses? And finally, consider: a 14-year-old athlete with a prolonged QTc, if cleared to continue sport by a clinician who missed the ECG finding, is at risk of sudden cardiac death on the field. What is your responsibility when you review an investigation, and how will you build a habit of systematic reporting that catches what a casual glance might miss?